Metalworking lubricant



hire

3,051,655 METALWGRKING LUBRICANT George E. Earlier, Norristown, Pa., assignor to Quaker Chemical Products Corporation, Conshohochen, Pa., a corporation of Pennsylvania No Drawing. Filed Nov. 1, 1957, Ser. No. 693,808 1 Claim. (Cl. 252-499) This 1' vention relates to lubricants for the lubrication of metals under conditions of working such as rolling, drawing, extruding, cutting, grinding, forging and spinning.

It is customary to use a variety of lubricants for metalworking depending on the operation and the re- ,quirements of the job. A particular characteristic of metalworking operations is the existence of high unit pressures. Consequently, the lubricant must maintain its lubrication under these boundary conditions. metalworking activities the surface friction must be low in order to prevent contributing to the heat generated by the metal deformation and to reduce the pressure necessary to obtain the desired degree of deformation such as in rolling or drawing. Under some conditions physical dissipation of heat, e.g., by water cooling, is required, and the lubricant should interfere with this cooling to a very minimum extent.

It is well known that fatty oils and fatty acids are widely used as metalworking lubricants because of their friction-reducing properties under high pressures, e.g., the use of palm oil in cold rolling steel. These boundary lubricating properties of the fatty oils involve physical and chemical adsorption of their polar constituents. There is much evidence that the long chain polar compounds in fats orient themselves at the surface and thus aid in maintaining low friction under high pressures. However, fatty oils have severfl disadvantages including gumrning, carbonizing, becoming rancid and having variable compositions. They also are subject to a fluctuating price structure, and some of the most useful fats such as palm oil are subject to scarcity during times of political unrest in many sections of the world.

It is an object of this invention to produce a new and superior metalworking lubricant. it is also an object of this invention to produce metalworking lubricants which obviate the use of fatty oils, or reduce the proportion of'fatty oils required for a given metal working operation. Another object of this invention is to produce lubricants superior to fatty oils. A corollary object of this invention is to produce a metalworking lubricant which will not gum, carhonize or otherwise decompose to produce a contaminated metal surface dillicult to clean. Compositions of this invention-leave essentially no residue after annealing of metal which has been stamped, drawn or rolled.

In accordance with this invention it has been found that a new and useful family of metalworking compounds may be prepared by reacting long chain amines with phosphoric acid. According to my invention, I use those amines containing at least one carbon chain possessing from 12 to 30 carbon atoms. They preferably are dior polyfunctional amines and may be primary, secondary or tertiary or a mixture of the three.

I believe these compounds may be generically represented by the following structural formula:

RI! u where R is an a chain possessing from 12 to 30 carbonatoms; R is selected from H, alkyl, ethoxy, polyethoxy, aminoalkyl, or ethoxy-lated aminoalkyl groups; R" is selected from H,

For most.

kyl group containing at least one carbon 3,051,655 Patented Aug. 28, 1962 alkyl, 'ethoxy, or polyethoxy groups; n is 1 to 3; and m is 1.01 2. x

As indicated, R may be substituted by an amino radical which, in turn, may have one or both of its hydrogen atoms replaced by alkyl groups or ethoxy or polyethoxy groups. When R is thus substituted by an amino group, In may be any value up to and including 2, whereby compounds of the following structural formula are produced:

where x is an integer of 1 to 3.

I believe the compounds of this invention are the primaryor secondary phosphate salts of the amines or mixtures of the two, (n=1 or 2) since it has been reported in the literature (Hoerr and Ralston, I.A.C.S. 64, 2824 (1942) that attempts to isolate the tertiary phosphates of long chain aliphatic-amines have been unsuccessful. However, I do not wish to limit the invention by this statement, particularly in view of the fact that I obtain excellent metalworking lubricants, when using the amines even in excess of the 3 amino groups per mol of phosphoric acid as indicated above.

Because of the ready dispersibility in diluents such as mineral oil or water, oxyethylated derivatives of the above described amines such as those in which these amines are condensed with one to-five mols of ethylene oxide per primary or secondary amino group are preferred. The ratio of alkylarnine to phosphoric acid may vary over a wire range depending on the application of the lubricant. For example, it may be as high as 2 or 3 mols of phosphoric acid per amine group in cases where simultaneous phosphatin-g of the steel is desirable such as in some compounds for making extremely severe draws. On the other hand it may be as low as 0.01 to 0.1 mol of phosphoric acid per amine group, where the lubricating requi ements are light or moderate or an alkaline agent is desired. Naturally, for most applications 0.1 to 0.5 mol of phosphoric acid per amine group is preferred. These compositions range from viscous liquids to waxy solids depending on the components.

'These metalworking lubricants are generally employed in a diluent such as mineral oil, preferably of lubricating viscosity, in amounts of from 0.5 to 50% :by weight of the compounds, or in water in the interest of economy or case of application, but they may be applied directly for severe operations. Also, these lubricants may be applied in a volatile diluent for ease of application and the diluent evaporated to leave a tenacious adherent film. Aside from their use directly as lubricants these compositions may be added to the common lubricating agents such as fats, mineral oils, synthetic lubricants, and silicones, or mixtures thereof to enhance the lubricating properties of the latter.

To these new lubricants in mineral oil there may be added the usual types of well known modifying additives such as viscosity improvers, anti-oxidants, thickeners,

graphite, molybdenum disulfide, sulfurized oils, chlorine EXAMPLE I 28 parts of alkylaminopropylamine, where flie alkyl group represents the hydrocarbon chains normally present in tallow, which fall in the approximate range of two 'by water hardness.

percent tetradecyl, 24 percent hexadecyl, 28 percent octadecyl, and 46 percent octadecenyl (available from Armour amine, where the alkyl group represents the hydrocarbon chain normally present in tallow (available from Armour & Co. as Duomeen T and from General Mills, Inc. as

' Diam 26), 20 parts tallow, and5 parts of a sulfurized a smooth, uniform pasteis obtained. This product is generally diluted with 3 to parts of water for use. It phosphates and lubricates in one operation when the metal is treated by a suitable means such as immersion or spraying preferably with the lubricant at a tempera-' ture of 140-180 F. This lubricant is used for drawing steel tubing as well as for the stamping, drawing or other 'wise forming of metal parts.

- EXAMPLE '11 14.1 parts of an alkylamine, where the alkyl group represents the hydrocarbon chain normally present in soya oil, which falls in the approximate range of '20 percent hexadecyl, 17 percent octadecyl, 26 percent octadecenyl,

and 37 percent octadecadienyl (available .from Armour &- Co. as Armeen S) is stirredvigorously while 6.9 parts of phosphoric acid (75%) diluted with 79.0 parts of water 7 is added slowly until a smooth viscous fluid is obtained.

Higher amines such as those derived from behenic,

, arachidic and erucic acids, and the acids obtainable from beeswax and carnauba wax are also suitable for preparing carbon atoms.

EXAMPLE III a 7.1 parts of a tertiary alkylamine condensed. with 5 "mols of ethyleneoxide, where the alkyl group represents an aliphatichighly branched chain hydrocarbon containing 18 to'24' carbon atoms and in which the amine group;

is attached to a tertiary carbon atom of the chain (avail able from Rohm & Haas Co. as Priminox 10) and 2.3 parts of an alkylaminopropylamine; where the alkyl group represents the hydrocarbon chain normally present in tallow (available from Armour & Co. as Duomeen T or from General Mills, Inc. as Diam 26) are melted together and stirred vigorously while 4 parts of monosodium phos-. phate dissolved in 86.6 parts of water isadded slowly "with stirring. A' smooth, very viscous fluid, which may set to a thixotropic solid on standing, is obtained. When applied to a steel surface at a dilution of 1:5 in water at 160 P. for 3 minutes, followed by drying, a strongly adherent film is formed. 7 The film serves as a good lubricant for drawing or spinning of the metal. Water dilutions of the lubricant are good grinding and cuttinglubricants and coolants.

' 7 EXAMPLE IV thenic oil" (200 SUS at 100 F.) at a temperature of 150 F. While stirring this mixture rapidly, 2.2 parts of phosphoricacid (75%) is added and the heating continued, raising theitemper-ature of the reaction mixture gradually to 275 F. and maintaining until a clear liquid is obtained and foaming has ceased; The foaming is caused by the boiling out of the water introduced with the phosphoric'acid. When applied 'to a metalsurface this lubricant serves as an efficient metalworkinglubricant for cutting, drawing and rolling. It is also self-emulsifythese' lubricants. These amines may contain up to petroleum oil containing" about 2% sulfur are heated together (about 130 F.) to give a clear liquid. 5.4 parts of phosphoric acid 75%)' is dissolved in 50 parts of water and 'the solution is added to the mixture of oils and amines with energetic stirring toform an emulsion. Thisprodu'ct is an effective metalworking lubricant. It is useful when diluted for cutting and grinding coolants. It is applied diluted 1:5 with water to steel tubing, the water evaporatedto leave tough adherent film and the 'tubing drawn to give an excellent uniform finish,

7 EXAMPLE VI A mixture of 5.3 parts of a polyoxyethyl alkylamino propylamine, where the alkyl group represents the hydro carbon chain normally present in tallow (available from ;Armour & Co. 'as Ethoduomeen T/ 13), 0.8 part of alkylaminopropylamines, where the alkyl group repre sents the .hydrocarbon'chain normally present in tallow, 61 parts of naphthenic lubricating oil having a viscosity of 200. SUS at 100 F., 3 parts stearic acid, 26.9 parts tallow and 2.5 parts of a sulfurized mineral oil containing about 2% sulfur is heated to 150 F. to give a clear liquid. To the clear oil described above is added with vigorous'stirring 0.50 part of phosphoric acid (75%) and the temperature is raised to 275 F. gradually and maintained there until clear and foaming (caused by boiling out of water) has ceased. This product is an excellent metalworking lubricant, particularly for rolling steel in a recirculating system, when diluted with 5 to 50 parts of water. It is also eiiective for cutting, grinding, drawing and other metalforming operations.

- EXAMPLE VH V V 4.5 parts'of a polyoxyethyl alkylaminopropylamine,

where the alkyl group represents the hydrocarbon chain normallypresent in coconut oil and where the polyoxyethyl represents the reaction productof 3 moles of ethylene oxide per mole of amine (available from Armour & Co. as Eethoduomeen C/ 13'), 0.8.part of alkylaminopropylarnine, where the alkyl group represents the hydrocarbon chain normallypresent in coconut oil (available from,Armour & Co. as Duomeen C and from General Mills, Inc. as Diam 21),'2.8 parts stearic acid, 2.5 parts sulfurized mineral oil containing about 2% sulfur and 89, parts of naphthenic petroleum oil having a viscosity of 1200 SUS at 100 F. are heated-to 140 F. to give 'a clear liquid. To the above rapidlystirred mixture of amines and oils there is added 0.4 part of phosphoric acid EXAMPLE VIII 8 partsof alkylaminopropylamine, where the alkyl group represents the hydrocarbon chains normally present in tallow (available from Armour & Co. as Duomeen T or from General Mills, Inc. as Diam 26) is melted and stirred with 87.9 parts of mineral oil having a viscosity of .1200 SUS at.100 F. to give a clear liquid. To

the oil solution of the'arnine is added with stirring 0.5 part of phosphoric'a'cid (75% )1 The mixture is heated to 280 F. and stirring'continued until a clear liquid is V 1 obtained; 2.8 parts of oleic acid is added to the above ing andefiicient when dispersed in water. It is unafiected EXAMPLE v 12.9 parts of a polyoxyethyl alkylaminopropylamine,

where the alkyl group represents the hydrocarbon chain 7 normally per molecule (available from Armour & Co. as EthoduomeenT/15'),'6.7 parts of an'alkylaminopropylsolution with stirring and the product is allowed to cool to room temperature. This product is a very suitable lubricant for drawing, rolling and cutting. It does not emulsify with water.

Employing "a modification of the Bowden-Leben apparatus -(Proc. Roy. Soc. 169, 371 (1939)) for measuring boundary friction in the presence of lubricated steel sliding "on steel under calculated pressures of 200,000 to EXAMPLE IX 45.2 parts of melissyl amine (C H NH is melted and dissolved in 200 parts of naphthenic oil (200 SUS at 100 F.) at a temperature of 180-200' F. While stirring vigorously, 1.3 parts of phosphoric acid (75%) is added and the heating continued, raising the temperature of the reaction mixture gradually to 275 F. and maintaining at that temperature until a clear liquid is obtained and the foaming has ceased. When applied to a metal surface this lubricant serves as an eflicient metalworking lubricant for cutting, drawing and rolling.

EXAMPLE X 19.3 parts of di-alkylarnine, where the alkyl groups represent the hydrocarbon chains normally present in hydrogenated tallow, which fall in the approximate range of 24 percent hexadecyl, 75 percent octadecyl, and one percent octadecenyl (available from Armour & Co. as Armeen ZHT or from General Mills, Inc. as Alamine H226) is dissolved in 78.3 parts of naphthenic petroleum oil having a viscosity of 200 SUS at 100 F. at a temperature of 180-200 F. to give clear liquid. To the above rapidly stirred solution is added 2.4 parts of phosphoric acid (75%) and the temperature raised gradually to 285 F. and maintained there until a clear liquid is obtained and foaming has ceased. This is arr-effective lubricant for drawing, cutting and rolling.

EXAMPLE XI 24.5 parts of dimethyldodecylamine (available from Distillation Products Division of Eastman Kodak Co.) is stirred vigorously while 13 parts of phosphoric acid (75%) diluted with 62.5 parts of water is added slowly and stirring is continued until a smooth, viscous fluid is obtained. This product is suitable for cutting and drawing. It may be diluted with water to an extent depending on its use.

Table l BOUNDARY LUBRICATING PROPERTIES OF METALWORKING LUBRICANTS T show the effects of carbon chain length of amine phosphate a homologous series was studied. The compositions were prepared by the procedure described in Example II, using 1 mol of phosphoric acid per molecular equivalent of amine and adjusting the water content to a constant 75%. For determining coeflicients of friction of steel, the compositions were diluted with 5 parts of water and applied to the steel plate on which the steel ball slides. From the data presented in Table II, it is evident that there is sharp change in eifectiveness between 10 and -12 carbon atoms in the alkyl chain.

Table II BOUNDARY L-UBRICATING PROPERTIES OF A HOMOL- OGOUS SERIES OF n-PRIMARY ALKYLAMINE PHOSPHATES ,Oompound Coef. of Friction n-Octylamine nhnsnh are 0. 14 n-Decylamine nhnsphate 0.13 n-Dodecylamine phosphate 0.10 n-Octadecylamine phosphate 0. 09

In addition to showing excellent friction-reducing properties under boundary conditions, these lubricants show excellent extreme pressure properties as measured with the Falex Lubricant Tester. Some of these data are shown in Table HI.

Table III FALEX SEIZURE TESTS ON METALWORKING LUBRICANT Load at Lubricant Conditions Seizure,

Lbs.

Example IV Applied directly 4, 500 Example IV Applied diluted 1:7 with 4, 500

mineral lubricating oil, SUS at 100 F. Example IV Applied diluted 1:15 with 3,250

' mineral lubricating oil,

100 SUS at 100 F. Example V Applied directly 4, 500 Example VT rln 4, 500 Palm Oil do 4, 500 Palm Oil Applied diluted 1:7 with 2,000

. mineral lubricating oil,

100 SUS at 100 F. Palm Oil Applied diluted 1:15 with 1, 500

mineral lubricating oil, 100 SUS at 100 F. Mineral Lubricating Oil, 100 Applied directly 1, 200

SUS at 100 F.

The compositions of this invention can be applied with excellent results to general metalworking operations such as grinding, cutting, drilling, drawing and rolling.

I claim:

As an improved metalworking lubricant, a composition consisting essentially of a mineral oil of lubricating viscosity and 0.5 to 50% by weight of a compound having the structural formula where R is an alkyl group containing a carbon chain possessing from ,12 to 30 carbon atoms; R is selected from the group consisting of H, aminopropyl and ethoxylated aminopropyl groups; R" is selected from the group consisting of H, and polyethoxy groups having 1 to 5 ethylene oxide residues; n is an integer 1 to 3; and m is an integer 1 to 2.

References Cited in the file of this patent UNITED STATES PATENTS 1955, page 2.

Bastian: Metal Working Lubricants, McGraw-Hill Book Co., N.Y., First ed., 1951, pp. 5 and 10. 

1. AS AN IMPROVED METALWORKING LUBRICANT, A COMPOSITION ITY AND 0.5 TO 50% BY WEIGHT OF A COMPOUND HAVING THE STRUCTURAL FORMULA 